Patients with clinically manifest OA typically consult the physician at time of irreversible cartilage destruction. This is due to the long time clinically silent progress of the disease. A biomarker screening profile for joint damage is a valuable tool for the detection of over use and joint damaging conditions especially in competitive sports. This would provide a method for OA risk assessment for the patient before clinical symptoms occur. For this the first step is the identification of biological substances reflecting pathologic changes in the joint.